Many fluids, particularly those to be administered to a patient, include undesirable or deleterious material that should be removed before the fluid is used for an intended purpose. For example, a parenteral fluid, that is, a fluid that is administered via a pathway other than through the alimentary canal, may include potentially pathogenic microorganisms, such as, for example, bacteria, that should not be administered to a patient. The parenteral fluid may include pyrogenic substances and/or particulate matter that should be removed before using the fluid.
Since the administration of a parenteral fluid including an undesirable material to a patient may cause an adverse effect, e.g., fever, in the patient receiving this fluid, it may be advisable to process the fluid to remove this material. Typically, a parenteral fluid is passed through a device including a porous medium to remove undesirable or deleterious matter. In some protocols, e.g., involving continuous and/or long term administration, different parenteral fluids are administered, and each fluid may be passed along the same flow path through the porous medium to remove this matter. For example, a patient receiving fluid replenishment, e.g., a continuous saline drip, may periodically require medicaments and/or nutrients, and each of these fluids may be passed through the same flow path through the porous medium.
However, there may be a number of drawbacks associated with some of the protocols summarized above. For example, while passing the fluid(s) through a porous medium may remove the undesirable material, this may also cause the loss of some of the parenteral fluid. For example, valuable parenteral fluid may be held up in the porous medium and/or the housing containing the porous medium. Fluid may be lost to the medium, e.g., due to absorption by the medium. As a result, this held up or lost fluid may be essentially unavailable to the patient, or may have to be flushed through the device by a carrier fluid, to be administered in the amount intended. The time required to flush this additional fluid may delay administration of the intended dose (e.g., a bolus dose) of the parenteral fluid. Additionally, in some situations, particularly those involving administration of precise amounts of fluid, it may be difficult to accurately administer the correct amount of filtered fluid. The problem may be magnified when only a small volume of fluid is to be administered.
There are other problems associated with the use of a single flow path passing through the same porous medium when processing parenteral fluids. For example, the same porous medium may not be suitable or equally efficient for processing different parenteral fluids. Thus, a porous medium suitable for passing a parenteral fluid such as saline may be less suitable for passing a different parenteral fluid, such as a parenteral fluid including an emulsion, e.g., a nutrient solution or an anesthetic.
Furthermore, it may be awkward and/or time consuming to add another parenteral fluid line, e.g., by "piggybacking." Additionally, properly controlling the flow paths and/or flow rates of the various fluids may be labor intensive.
Also, when processing and/or administering fluids, it may be desirable to minimize the presence of, or interference by, air or gas. For example, particularly in those protocols involving processing of small volumes of fluid, it may be difficult to pass a liquid through a porous medium if air is present, since the air may block the porous medium. Also, since air should not be administered to a patient, it may be desirable to minimize the presence of air, e.g., by venting the gas from the fluid treatment device that includes the porous medium.
Accordingly, there is an unanswered need in the art for a method, device and system for efficiently processing a fluid, particularly a parenteral fluid, to remove undesirable material. There is also a need for a method, device and system for efficiently processing different parenteral fluids. Preferably, different parenteral fluids may be processed so that air or gas may be separated from the parenteral fluids and/or so that the fluids may be efficiently processed while air is present.
Moreover, there is also a need for a device, system and method for processing a fluid that provides for increasing the amount of fluid available for an intended use, for example, for administration to a patient.
These and other advantages of the present invention will be apparent from the description as set forth below.